Generally, electrophotographic liquid developers are those which are prepared by dispersing an organic or inorganic pigment or dye such as carbon black, Nigrosine, Phthalocyanine Blue, etc. and a natural or synthetic resin such as an alkyd resin, an acrylic resin, rosin, a synthetic rubber, etc. in a liquid with high electrical insulation property and low dielectric constant, such as a petroleum type aliphatic hydrocarbon, and adding a polarity controlling agent, such as a metal soap, lecithin, linseed oil, a higher aliphatic acid, polymers containing vinyl pyrrolidone, etc. In these developers, the resin is dispersed in the form of granule as insoluble latex grains such as a diameter of several .mu.m to several hundred .mu.m is obtained. In prior liquid developers, since the dispersion stabilizing soluble resin or the polarity controlling agent does not sufficiently bond to the insoluble latex grains, the dispersion stabilizing soluble resin and the polarity stabilizing agent can easily diffuse in the solution. Therefore, there is the disadvantage that the dispersion stabilizing soluble resin separates from the insoluble latex grains with precipitation, aggregation or accumulation of grains occurring or the polarity becomes obscure, when the developer is stored for a long time or is repeatedly used. Further, since it is difficult to disperse the grains again once they are aggregated or accumulated, the grains adhere to all parts of the developing apparatus to result in difficulties such as contamination of image parts or blockage of the liquid flow pump. In order to eliminate these disadvantages, the dispersion stabilizing soluble resin has been chemically bonded to the insoluble latex grains as disclosed in U.S. Pat. No. 3,990,980. However, according to experimental results of the present inventors, grains produced as described in U.S. Pat. No. 3,990,980 have the disadvantages that the particle size distribution curve has two or more peak values or the particle size distribution is broad and it is difficult to produce a uniform particle size and reproduction is not good. Generally, since the performance of liquid developers comprising dispersed resin grains, such as storage property, stability and image reproduction, is largely dependent on the particle size of the resin grains, a marked deterioration of performance occurs, if the particle size is not uniform.